The desirability of identifying or discovering new antimicrobial agents is widely recognized. New antimicrobial agents are desired for several reasons; these include, but are not limited to, responding to the problem created by the development of microbe strains resistant to known antimicrobials, the occurrence of undesirable interactions of certain known antimicrobials with the medium or product in which the antimicrobial is used, and high toxicity of certain known antimicrobials to certain non-target organisms such as mammals.
U.S. Pat. Nos. 4,172,892 and 4,388,314 disclose a large number of acids, one of which has the formula: EQU HOOCCH.sub.2 --S--C.tbd.C--C.tbd.N
which is used as a reactant in a process to produce a compound of the formula: ##STR1## wherein X is a free or esterified carboxy group and B is a substituted tetrazolyl or thiadiazolyl radical or a heterobicyclic ring. This compound is taught to be useful in pharmaceutical and veterinary compositions, as well as antibacterial activities. This reference, however, provides no teaching that the acid of the formula: EQU HOOCCH.sub.2 --S--C.tbd.C--C.tbd.N
is itself useful as an antimicrobial agent.
U.S. Pat. No. 5,039,702 discloses an .alpha.-halo-.beta.-(substituted)thio-acrylonitrile of the formula: ##STR2## wherein X is a halogen and R is a lower alkyl, aryl, aralkyl, heterocyclo, or a thiocarbonyl group. This compound is taught to be useful as an effective antimicrobial agent.
This reference does not, however, provide any teaching that the .alpha.-halo-.beta.-(substituted)thioacrylonitrile may be further reacted to prepare the substituted 3-thio-2-propynenitriles of the present invention, or that such substituted 3-thio-2-propynenitriles would be effective antimicrobial agents.